Mercury-gage.



Patented Dec. 1, 1914.

H. E. LONG.

MERCURY GAGE. APPLIGATIION FILED AUG. 28, 1913 1,1 19,706"

H. E. LONG.

' MERCURY GAGE.

APPLICATION FILED AUG. 28, 1913.

Patented Dec. 1, 1914.

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HOWARD E. LONG, 0F LOCKPORT, NEW YORK, ASSIGNOR TO AMERICAN DISTRICT STEAM COMPANY, OF NORTH TONAWANDA, NEW YORK, A CORPORATION OF NEW YORK.

. MERCURY-GAGE.

Application filed August 28, 1913.

Gages, of which the following is a specification, reference being had therein to the accompanying drawing.

This invention relates broadly to gages.

The object of the invention is to provide a gage, of the so-called mercury-gage type, which is simple in construction, and

automatic, effective and certain in opera-' tion; and one in which the index-tube is open at the top.

Another object is to provide a gage in which certain of the instrumentalities employed are adapted to operate in such manner that, in the event of sudden excess of boiler pressure on the steam-heating system-wherein is used a comparatively low pressure, not to exceed three pounds, say the mercury in the gage'will be prevented from being forced beyond a predetermined point and, thus, 'will preclude the escape of the mercury from the top of the indextube.

With these and other objects in view, the invention resides in a structure in which there is included (among other instrumentalities) an index-tube containing a mercury column and a float therein (in the nature of a valve) constructed of a material which is light in weight and which is unaffected by the mercury. The valve is so designed and positioned that any sud den excess of pressure will float it to a seat and effect a closure to prevent the escape of the mercury from the tube. This device.

therefore, operates as a check-valve and serves a dual function, namely, first, to prevent loss of mercury from the tube while acting under excess pressure from below; and, secondly, whenever a slight vacuum below the fioatvalve (caused by the mercury receding when steam-pressure is removed) coacts with the atmospheric pressure above it, to eflect. a movement of the valve and permit entrance of air to the top of the column, thereby breaking the existing vacuum and permitting the mercury to indicate pressure correctly. The check-valve of my improvement is under pressure only at such time as the pressure on the gage 1s Specification of Letters Patent.

Serial No. 787,169.

in excess of that for which the gage is designed, wherefore it may be regarded as an emergency expedient, and is not designed to operate as an indicating-instrumentality. The invention also resides broadly in the features of construction, combination of elements and instrumentalities, and arrangement of parts, and in various aggroupments thereof, all as will be exemplified in the construction hereinafter set forth; and the scope of the application of which will be indicated in the claims hereto appended.

In order that this invention may be more clearly made comprehensive to those skilled in its related art, drawings illustrating one -of the manv possible utilizations of the same are appended hereto as a part of this disclosure; it being manifest that other possible utilizations and embodimentsthose employing the underlying principles of my inventionfal1 within the spirit thereof and, also, within the objects contemplated thereby.

In said drawings: Figure 1 is a view in front elevation of a gage constructed in accordance with my invention; Fig. 2 is a view in central vertical section thereof; Figs. 3 and 4 are views, respectively, in top and bottom plan of the structure; Fig. 5 is a fragmentary view in central vertical section, on an enlarged scale, of the upper structure and showing particularly the float-valve, its

housing, and the means of communication between the housing and the index-tube; Figs. 6 and 7 are similar views of the valve and its seat-member unassembled.

In the drawings, the reference-numeral 1 designates the index-tube or leg of a gage; and 2 the water-tube or back leg thereof. The back-tube 2 includes a primary watercontaining chamber 3 which communicates, as by the opening 4:, with a form of connection between the gage and the boiler (not shown), and a mercury-containing chamber 5 which communicates with the primary chamber at its top, as shown. The upper end of the chamber 2 is closed, as by a screw-plug 6, and through which the mercury-mass 7 may be introduced when desired or necessary. The two tubes or legs of the gage are connected together, as by the webs 8 and 9, at the top and bottom respectively.

Disposed between the tubes and formed as an integral body therewith, is a scale Patented Dec. l, 191%.

element 14 tapped into the base portion 15 of the structure. Preferably and as shown,

1 said base-portion, as well as the web 9, is

i' so provided with a channel 16 which connects at its upper end with the bore 13 of the tube 12, and at its lower end with the chamber 5 and is adapted, like said chamber 5, to hold a portion of the body of mercury. It may here be stated that the mercury in said chamber is shown in the position in which it rests when the water-column 3 is filled. 1n this instance, the top of the mercury-column occupies a position in the glass tube approximately in line with the zeropoint on the gage-scale 11.

The upper end of the glass tube 12 projects into another threaded element 17 tapped into the top portion 18 of the structure. The lower end of said element 17 is providedwith a recess 19 which with a similarly formed depression 20 in the portion 18,

constitute a stuffing-box 21 adapted to be filled with suitable packing to hold the glass tube in position. Tapped into said threaded element 17 is a valve-seat member 22 provided with a chamber 23. and a stem-guiding channel 24,-, which is always open. Housed within the chamber 23 is a float-valve member 25 provided with an upstanding stem 25. Preferably and as shown a suitable packing washer 26 is interposed between the lower end of the threaded element 22 and the-top of the glass tube 12, and this serves as the normal support for the valvemember 25.

It will be obvious that, as the elements of the structure are shown as in their normal position, any rise in pressure will actuate the mercury-column and the degree of pressure will be indicated on the gage-scale. In the present instance, the gage is shown as operative for a three-pounds pressure, and the valve itself, will be put under pressure only when the steam pressure on the gage is in excess of that. In the event of a sudden excess of boiler pressure on the steam-system, the mercury rises and puts the valve, itself, under pressure. If now, that pressure then becomes abnormal, the valve will be floated ofl its normal support 26 and against the seat 27 and effect a'tight closure to prevent outflow and escape of the mercury through the channel 24 which, as already stated, is normally open to the atmosphere.

Now, as the mercury reeedes in the glass tube, there is created a slight vacuum between the top of the mercury column and the bottom of the valve, so that air passing through the channel 24, the valve then having dropped somewhat, it permits the air to enter to the space above the mercury-column and break the vacuum, whereupon the mercury will perform its intended function of properly indicating pressure in the glass tube 12.

From the foregoing, it will be perceived that 1 have succeeded in devising a gage which is automatic in its operation and, thus, well adapted to achieve the several objects and ends in View. The structure is simple and compact in form, is peculiarly well suited for use in connection with steamsupply systems; and the parts of which is formed are so constructed as to permit of its convenient application to existing structures. It is, also to be understood that the language used in the following claims is intended to cover all of the generic and specifie features, of the invention, which, as a matter of language, might be said to fall therebetween.

As many changes can be made in the above-described construction and other embodiments thereof can be made without departing from the scope thereof, it is intend,-

ed that all matter contained in the foregoing .tion: a water-tube; an index-tube communicating therewith; a supporting connection between the tubes provided with a channel extending in a plane at an angle to the horizontal; a single fluid body sustained in said connection and normally tending to recede into the water-tube and adapted to be forced by pressure in said tube at varying heights into said index-tube; a valve-seat member at the top of said index-tube provided with chamber normally open to the atmosphere at its top; and a float valve housed within said chamber and adapted to rise under the influence of said fluid-body to close said...

seat-memberagainst intake of air and alsd" against escape therefrom of said fluid-body under abnormal pressure in the water-tube.

2. A mercury pressure-gage including in combination: a water-tube; an index-tube;

a channel'extending between said tubes and cut at an angle to the horizontal; a single mercury-column in the channel and normally extending into both tubes and having a tendency to recede into the water-tube and.

Water-tube; a gage-scale arranged in juxtaposition to said index-tube, an open-ended seat-member at the top of the index-tube and normally open to the atmosphere; and a float-valve housed therein and adapted to i adapted to be influenced by pressure in said'125 nuance 3. A mercury pressure-gage including in combination a Water-tube; an index-tube; a fluid-supporting connection between the 'tubes and provided with a channel cut at an angle to the horizontal a mercury-column normally occupying a position in the lower portions of the two tubes and in the inclined channel; an open-ended seat-member at the top of the index-tubenormally open to the atmosphere; and a float-valve having a body-portion providedwith a conical surface and with a stem extending from said surface into one of the openings in the seatmember, said valve being movable under abnormal pressure within the tubes to close said seat-member against intake of air and also against escape therefrom of said mercury-column. 1

. In testimony whereof I afix my signature in presence of two Witnesses.

HOWARD E. LONG.

Witnesses:

GnARLEs R. Brsnor, WALTER J. KLINE. 

